Journal: Cells

Article Title: Origin, Diversity, and Multiple Roles of Enzymes with Metallo-β-Lactamase Fold from Different Organisms

doi: 10.3390/cells12131752

Figure Lengend Snippet: β-lactamase fold enzymes with reported enzymatic activity from the different domains of life.

Article Snippet: Interestingly, it has been reported that the enzymatic characterisation of the L-ascorbate 6-phosphate lactonase enzyme from S. pneumoniae ATCC 49136 shows a β-lactamase activity since the purified enzyme is able to hydrolyse both nitrocefin and ampicillin-based antibiotics [ ].

Techniques: Activity Assay

Journal: BMC Microbiology

Article Title: Genomic and phenotypic profiling of Staphylococcus aureus isolates from bovine mastitis for antibiotic resistance and intestinal infectivity

doi: 10.1186/s12866-023-02785-1

Figure Lengend Snippet: Antibiotic-resistance mechanisms and virulence factors in S. aureus isolates. a Assessment of efflux pump activity in five antibiotic-resistant and five susceptible isolates. EtBr efflux assay was performed using 3 µg/mL of EtBr and 30 µg/mL of CPZ. The fluorescent intensity (530 nm/590 nm) was monitored for 60 min after reenergizing the bacterial cells to trigger EtBr efflux with glucose (0.4% v/v). b Assessment of ß-lactamase enzyme activity in the isolates. The isolates were subjected to a Nitrocefin assay where the absorbance of the cell-free extract mixed with Nitrocefin was detected at 490 nm for 15 min. c Distribution of hemolysin manifestation by the 43 isolates. d Alpha hemolysin manifestation by Sa30. Each isolate was cultured in TSA plates with 5% sheep blood for 24 h. The hemolysis was detected visually by the translucency around the bacterial colony. e Distribution of biofilm-forming ability by the 43 isolates. The biofilm formation was assessed using a crystal violet assay. All isolates were classified into weak, moderate, and strong biofilm-formers based on their biofilm-forming ability. f Fluorescence microscopic image of extracellular polymeric substances (EPS) and Sa30 cells. A green (505 nm) filter was used to acquire the GFP-labeled Sa30 biofilms using a high-content screening microscope, Cell Discoverer 7. Alphabets (in tabular data) indicate a significant difference ( p < 0.05). ‘N/A’ stands for not applicable. More data on the resistance mechanisms and virulence factors are provided in Tables S and S . The experiment was performed in quadruplicates and repeated thrice to ensure reproducibility

Article Snippet: S. aureus ATCC 25923 with no ß-lactamase enzyme activity was used as a reference strain.

Techniques: Activity Assay, Cell Culture, Crystal Violet Assay, Fluorescence, Labeling, High Content Screening, Microscopy

Journal: Scientific Reports

Article Title: Antimicrobial susceptibilities and comparative whole genome analysis of two isolates of the probiotic bacterium Lactiplantibacillus plantarum, strain ATCC 202195

doi: 10.1038/s41598-021-94997-6

Figure Lengend Snippet: Antimicrobial susceptibility and minimum inhibitory concentrations of L. plantarum ATCC 202195-A and L. plantarum ATCC 202195-B.

Article Snippet: L. plantarum ATCC 202195-B was also tested for beta-lactamase activity using Nitrocefin (BD BBL, New Jersey, USA).

Techniques: Diffusion-based Assay, Activity Assay